Field of the Invention
The invention relates to a forming tool for hot forming and partially press hardening a workpiece made of sheet steel, comprising a die, a punch which can be inserted into a cavity of the die to form the workpiece, and a cooling device. In particular, the invention relates to a method for hot forming and partially press hardening a workpiece made of sheet steel, in which the workpiece is heated prior to forming and is subsequently hot formed in a forming tool comprising a die and a punch which can be inserted into a cavity of the die, the forming tool comprising a cooling device.
Description of the Related Art
The hot forming of blanks made of higher strength and super high strength steels to produce press hardened components has become established in vehicle construction in recent years. In this context, numerous ideas for producing partially hardened components having different textures have also been developed, inter alia. An idea known from DE 10 2006 019 395 A1 is the heating of a blank consisting of suitable steel to a temperature higher than the austenitising temperature and the immediately subsequent forming in a hot forming tool which is provided in at least one region with a heating device for local setting of a weaker texture. However, this known idea has the drawback that at least one heating device must be provided, which results in considerable operating costs. In addition, the continuous exposure of the corresponding active surface of the forming tool to heat has a negative effect on the service life (lifetime) thereof.